1. Field of the Invention
The present invention relates to a composite substrate.
2. Description of the Related Art
It has been known to manufacture an elastic wave device by providing electrodes on a composite substrate in which a supporting substrate and a piezoelectric substrate are bonded to each other. The elastic wave device is used, for example, as a band pass filter in communication equipment, such as a mobile phone. Furthermore, in a known composite substrate, a piezoelectric substrate is composed of lithium niobate or lithium tantalate and a supporting substrate is composed of silicon, quarts, or a ceramic (refer to Patent Literature 1). Examples of the ceramic described therein include those widely used as a package material.